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<FONT color="green">001</FONT>    package project3.lex;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import project3.three.Node;<a name="line.3"></a>
<FONT color="green">004</FONT>    import project3.three.ParserException;<a name="line.4"></a>
<FONT color="green">005</FONT>    <a name="line.5"></a>
<FONT color="green">006</FONT>    /**<a name="line.6"></a>
<FONT color="green">007</FONT>     * A &lt;i&gt;Constant&lt;/i&gt; token. This is not needed for assignment 1, but is<a name="line.7"></a>
<FONT color="green">008</FONT>     * included in the &lt;i&gt;lex&lt;/i&gt; package to make it easier to read the code<a name="line.8"></a>
<FONT color="green">009</FONT>     * in project 3.<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * &lt;p&gt;<a name="line.11"></a>
<FONT color="green">012</FONT>     * &lt;pre&gt;<a name="line.12"></a>
<FONT color="green">013</FONT>     * Sytnax: "'" &lt;b&gt;Non-QuoteCharacter&lt;/b&gt;* [["'" "'"]+<a name="line.13"></a>
<FONT color="green">014</FONT>     *             &lt;b&gt;Non-QuoteCharacter&lt;/b&gt;]* "'"<a name="line.14"></a>
<FONT color="green">015</FONT>     * &lt;/pre&gt;<a name="line.15"></a>
<FONT color="green">016</FONT>     *<a name="line.16"></a>
<FONT color="green">017</FONT>     * &lt;p&gt;<a name="line.17"></a>
<FONT color="green">018</FONT>     * &lt;pre&gt;<a name="line.18"></a>
<FONT color="green">019</FONT>     * Domain Definition:<a name="line.19"></a>
<FONT color="green">020</FONT>     *     type       : TokenType<a name="line.20"></a>
<FONT color="green">021</FONT>     *     value      : String<a name="line.21"></a>
<FONT color="green">022</FONT>     *     lineNumber : int<a name="line.22"></a>
<FONT color="green">023</FONT>     *<a name="line.23"></a>
<FONT color="green">024</FONT>     * Instance Invariant:<a name="line.24"></a>
<FONT color="green">025</FONT>     *     type = TokenType.STRING<a name="line.25"></a>
<FONT color="green">026</FONT>     * &lt;/pre&gt;<a name="line.26"></a>
<FONT color="green">027</FONT>     *<a name="line.27"></a>
<FONT color="green">028</FONT>     * Last Modified: 10 Jan 2006<a name="line.28"></a>
<FONT color="green">029</FONT>     *<a name="line.29"></a>
<FONT color="green">030</FONT>     * @author Scott N. Woodfield<a name="line.30"></a>
<FONT color="green">031</FONT>     * @version 1.0<a name="line.31"></a>
<FONT color="green">032</FONT>     * @see &lt;a href="../../srchtml/lex/Constant.html"&gt;Source Code&lt;/a&gt;<a name="line.32"></a>
<FONT color="green">033</FONT>     */<a name="line.33"></a>
<FONT color="green">034</FONT>    public class Constant <a name="line.34"></a>
<FONT color="green">035</FONT>        extends Argument<a name="line.35"></a>
<FONT color="green">036</FONT>    {<a name="line.36"></a>
<FONT color="green">037</FONT>    //Constants<a name="line.37"></a>
<FONT color="green">038</FONT>    //  TokenType type       -- inherited from Token through Argument<a name="line.38"></a>
<FONT color="green">039</FONT>    //  String    value      -- inherited from Token through Argument<a name="line.39"></a>
<FONT color="green">040</FONT>    //  int       lineNumber -- inherited from Token through Argument<a name="line.40"></a>
<FONT color="green">041</FONT>    <a name="line.41"></a>
<FONT color="green">042</FONT>    //Domain Implementation -- Inherited from Token<a name="line.42"></a>
<FONT color="green">043</FONT>    <a name="line.43"></a>
<FONT color="green">044</FONT>    //Constructors<a name="line.44"></a>
<FONT color="green">045</FONT>        /**<a name="line.45"></a>
<FONT color="green">046</FONT>         * Constructs a &lt;i&gt;Constant&lt;/i&gt; from a type, value, and lineNumber<a name="line.46"></a>
<FONT color="green">047</FONT>         *<a name="line.47"></a>
<FONT color="green">048</FONT>         * &lt;p&gt;<a name="line.48"></a>
<FONT color="green">049</FONT>         * &lt;table&gt;<a name="line.49"></a>
<FONT color="green">050</FONT>         *   &lt;tr&gt;<a name="line.50"></a>
<FONT color="green">051</FONT>         *     &lt;td valign=top&gt;<a name="line.51"></a>
<FONT color="green">052</FONT>         *       &lt;b&gt;Precondition&lt;/b&gt;:<a name="line.52"></a>
<FONT color="green">053</FONT>         *     &lt;/td&gt;<a name="line.53"></a>
<FONT color="green">054</FONT>         *     &lt;td valign=top&gt;<a name="line.54"></a>
<FONT color="green">055</FONT>         *       Token.Precondition<a name="line.55"></a>
<FONT color="green">056</FONT>         *     &lt;/td&gt;<a name="line.56"></a>
<FONT color="green">057</FONT>         *     &lt;td valign=top&gt;<a name="line.57"></a>
<FONT color="green">058</FONT>         *     &lt;/td&gt;<a name="line.58"></a>
<FONT color="green">059</FONT>         *   &lt;/tr&gt;<a name="line.59"></a>
<FONT color="green">060</FONT>         *   &lt;tr&gt;<a name="line.60"></a>
<FONT color="green">061</FONT>         *     &lt;td valign=top&gt;<a name="line.61"></a>
<FONT color="green">062</FONT>         *       &lt;b&gt;Postcondition&lt;/b&gt;:<a name="line.62"></a>
<FONT color="green">063</FONT>         *     &lt;/td&gt;<a name="line.63"></a>
<FONT color="green">064</FONT>         *     &lt;td valign=top&gt;<a name="line.64"></a>
<FONT color="green">065</FONT>         *       Token.Postcondition<a name="line.65"></a>
<FONT color="green">066</FONT>         *     &lt;/td&gt;<a name="line.66"></a>
<FONT color="green">067</FONT>         *     &lt;td valign=top&gt;<a name="line.67"></a>
<FONT color="green">068</FONT>         *     &lt;/td&gt;<a name="line.68"></a>
<FONT color="green">069</FONT>         *   &lt;/tr&gt;<a name="line.69"></a>
<FONT color="green">070</FONT>         * &lt;/table&gt;<a name="line.70"></a>
<FONT color="green">071</FONT>         *<a name="line.71"></a>
<FONT color="green">072</FONT>         * @param value the value of the constant.<a name="line.72"></a>
<FONT color="green">073</FONT>         * @param lineNumber the line number this token was found on.<a name="line.73"></a>
<FONT color="green">074</FONT>         *<a name="line.74"></a>
<FONT color="green">075</FONT>         * @throws ParserException<a name="line.75"></a>
<FONT color="green">076</FONT>         * @see &lt;a href="../../srchtml/lex/Constant.html#StdConstructor"&gt;Source Code&lt;/a&gt;<a name="line.76"></a>
<FONT color="green">077</FONT>         */<a name="line.77"></a>
<FONT color="green">078</FONT>        public Constant(String value, int lineNumber)<a name="line.78"></a>
<FONT color="green">079</FONT>            throws ParserException<a name="line.79"></a>
<FONT color="green">080</FONT>        {<a name="line.80"></a>
<FONT color="green">081</FONT>            super(TokenType.STRING, value, lineNumber);<a name="line.81"></a>
<FONT color="green">082</FONT>        }<a name="line.82"></a>
<FONT color="green">083</FONT>    <a name="line.83"></a>
<FONT color="green">084</FONT>        /**<a name="line.84"></a>
<FONT color="green">085</FONT>         * Constructs a &lt;i&gt;Constant&lt;/i&gt; from a &lt;b&gt;Token&lt;/b&gt;.<a name="line.85"></a>
<FONT color="green">086</FONT>         *<a name="line.86"></a>
<FONT color="green">087</FONT>         * &lt;table&gt;<a name="line.87"></a>
<FONT color="green">088</FONT>         * &lt;p&gt;<a name="line.88"></a>
<FONT color="green">089</FONT>         *   &lt;tr&gt;<a name="line.89"></a>
<FONT color="green">090</FONT>         *     &lt;td valign=top&gt;<a name="line.90"></a>
<FONT color="green">091</FONT>         *       &lt;b&gt;Precondition&lt;/b&gt;:<a name="line.91"></a>
<FONT color="green">092</FONT>         *     &lt;/td&gt;<a name="line.92"></a>
<FONT color="green">093</FONT>         *     &lt;td valign=top&gt;<a name="line.93"></a>
<FONT color="green">094</FONT>         *       token &lt;i&gt;instanceof&lt;/i&gt; &lt;b&gt;Constant&lt;/b&gt;<a name="line.94"></a>
<FONT color="green">095</FONT>         *     &lt;/td&gt;<a name="line.95"></a>
<FONT color="green">096</FONT>         *     &lt;td valign=top&gt;<a name="line.96"></a>
<FONT color="green">097</FONT>         *     &lt;/td&gt;<a name="line.97"></a>
<FONT color="green">098</FONT>         *   &lt;/tr&gt;<a name="line.98"></a>
<FONT color="green">099</FONT>         *   &lt;tr&gt;<a name="line.99"></a>
<FONT color="green">100</FONT>         *     &lt;td valign=top&gt;<a name="line.100"></a>
<FONT color="green">101</FONT>         *       &lt;b&gt;Postcondition&lt;/b&gt;:<a name="line.101"></a>
<FONT color="green">102</FONT>         *     &lt;/td&gt;<a name="line.102"></a>
<FONT color="green">103</FONT>         *     &lt;td valign=top&gt;<a name="line.103"></a>
<FONT color="green">104</FONT>         *       this.equals(token)<a name="line.104"></a>
<FONT color="green">105</FONT>         *     &lt;/td&gt;<a name="line.105"></a>
<FONT color="green">106</FONT>         *     &lt;td valign=top&gt;<a name="line.106"></a>
<FONT color="green">107</FONT>         *     &lt;/td&gt;<a name="line.107"></a>
<FONT color="green">108</FONT>         *   &lt;/tr&gt;<a name="line.108"></a>
<FONT color="green">109</FONT>         * &lt;/table&gt;<a name="line.109"></a>
<FONT color="green">110</FONT>         *<a name="line.110"></a>
<FONT color="green">111</FONT>         * @param token the constant &lt;b&gt;Token&lt;/b&gt; we will copy from.<a name="line.111"></a>
<FONT color="green">112</FONT>         * @see &lt;a href="../../srchtml/lex/Constant.html#CopyConstructor"&gt;Source Code&lt;/a&gt;<a name="line.112"></a>
<FONT color="green">113</FONT>         */<a name="line.113"></a>
<FONT color="green">114</FONT>        public Constant(Token token)<a name="line.114"></a>
<FONT color="green">115</FONT>            throws ParserException<a name="line.115"></a>
<FONT color="green">116</FONT>        {<a name="line.116"></a>
<FONT color="green">117</FONT>            super(token);<a name="line.117"></a>
<FONT color="green">118</FONT>            assert token instanceof Constant;<a name="line.118"></a>
<FONT color="green">119</FONT>        }<a name="line.119"></a>
<FONT color="green">120</FONT>    <a name="line.120"></a>
<FONT color="green">121</FONT>    //Queries<a name="line.121"></a>
<FONT color="green">122</FONT>        /**<a name="line.122"></a>
<FONT color="green">123</FONT>         * Convert the constant to a string.<a name="line.123"></a>
<FONT color="green">124</FONT>         *<a name="line.124"></a>
<FONT color="green">125</FONT>         * &lt;p&gt;<a name="line.125"></a>
<FONT color="green">126</FONT>         * &lt;table&gt;<a name="line.126"></a>
<FONT color="green">127</FONT>         *   &lt;tr&gt;<a name="line.127"></a>
<FONT color="green">128</FONT>         *     &lt;td valign=top&gt;<a name="line.128"></a>
<FONT color="green">129</FONT>         *       &lt;b&gt;Precondition&lt;/b&gt;:<a name="line.129"></a>
<FONT color="green">130</FONT>         *     &lt;/td&gt;<a name="line.130"></a>
<FONT color="green">131</FONT>         *     &lt;td valign=top&gt;<a name="line.131"></a>
<FONT color="green">132</FONT>         *       none<a name="line.132"></a>
<FONT color="green">133</FONT>         *     &lt;/td&gt;<a name="line.133"></a>
<FONT color="green">134</FONT>         *     &lt;td valign=top&gt;<a name="line.134"></a>
<FONT color="green">135</FONT>         *     &lt;/td&gt;<a name="line.135"></a>
<FONT color="green">136</FONT>         *   &lt;/tr&gt;<a name="line.136"></a>
<FONT color="green">137</FONT>         *   &lt;tr&gt;<a name="line.137"></a>
<FONT color="green">138</FONT>         *     &lt;td valign=top&gt;<a name="line.138"></a>
<FONT color="green">139</FONT>         *       &lt;b&gt;Postcondition&lt;/b&gt;:<a name="line.139"></a>
<FONT color="green">140</FONT>         *     &lt;/td&gt;<a name="line.140"></a>
<FONT color="green">141</FONT>         *     &lt;td valign=top&gt;<a name="line.141"></a>
<FONT color="green">142</FONT>         *       result =  "'" + value + "'"<a name="line.142"></a>
<FONT color="green">143</FONT>         *     &lt;/td&gt;<a name="line.143"></a>
<FONT color="green">144</FONT>         *     &lt;td valign=top&gt;<a name="line.144"></a>
<FONT color="green">145</FONT>         *     &lt;/td&gt;<a name="line.145"></a>
<FONT color="green">146</FONT>         *   &lt;/tr&gt;<a name="line.146"></a>
<FONT color="green">147</FONT>         * &lt;/table&gt;<a name="line.147"></a>
<FONT color="green">148</FONT>         * @return the lexical representation of the &lt;b&gt;Constant&lt;/b&gt;.<a name="line.148"></a>
<FONT color="green">149</FONT>         * @see &lt;a href="../../srchtml/lex/Constant.html#toString"&gt;Source Code&lt;/a&gt;<a name="line.149"></a>
<FONT color="green">150</FONT>         */<a name="line.150"></a>
<FONT color="green">151</FONT>        public String toString()<a name="line.151"></a>
<FONT color="green">152</FONT>        {<a name="line.152"></a>
<FONT color="green">153</FONT>             return "'" + value + "'";<a name="line.153"></a>
<FONT color="green">154</FONT>        }<a name="line.154"></a>
<FONT color="green">155</FONT>    }<a name="line.155"></a>




























































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